TOUCH SENSING CIRCUIT CAPABLE OF ADJUSTING RECEPTION FREQUENCY BAND, AND TOUCH SENSING SYSTEM HAVING SAME

摘要

The present invention introduces a touch sensing circuit that adjusts a reception frequency band, which adjusts a width of a reception frequency band of a driving signal applied from a driving electrode of a touch screen panel and transferred to a reception electrode of the touch screen panel. The touch sensing circuit adjusts the width of the reception frequency band of the driving signal, which is applied from the driving electrode of the touch screen panel and transferred to the reception electrode of the touch screen panel, by using a high pass filter prepared in the form of a differentiator and a low pass filter prepared in the form of an integrator. In the present invention, resistance values of a plurality of embedded resistors and capacitance of a capacitor are adjusted, so that a driving signal is selectively received according to frequencies, and a received driving signal is amplified with a predetermined amplitude. Accordingly, since a separated filter for removing a noise component included in the driving signal is not required, a system is simplified.

主权项

1. A touch sensing circuit, in which a coupling capacitor is generated in a node in which a driving electrode and a reception electrode of a touch screen panel cross each other and a frequency bandwidth of a driving signal applied from the driving electrode and received in the reception electrode is adjusted, the touch sensing circuit comprising:
a high pass filter configured to allow only a high frequency component of the driving signal to pass therethrough; and a low pass filter configured to allow only a low frequency component of a signal, which is output from the high pass filter, to pass therethrough, wherein the high pass filter comprises: the coupling capacitor having a first terminal connected to the reception electrode; a first resistor connected to a second terminal of the coupling capacitor, the first terminal facing the second terminal; a first amplifier having a first input terminal grounded, a second input terminal connected to a second terminal of the first resistor, and an output terminal through which a differentiation signal is output, the first input terminal facing the second input terminal; and a second resistor having a first terminal connected to the second input terminal of the first amplifier, and a second terminal connected to an output terminal of the first amplifier, the first terminal facing the second terminal, wherein the touch sensing circuit adjusts a width of a reception frequency band.